Enormous investments in AIDS related research and in public education have not been able to stem the worldwide pandemic. The consequences of this are most dire in developing parts of the world where transmission rates continue to increase at alarming rates, with women being particularly vulnerable to infection. Development of a protective vaccine is not likely in the short-term, thus the availability of alternative means of HIV infection prevention is critical. Effective microbicides administered vaginally may be an important means of prevention that have the further advantage of empowering women who are unable to negotiate condom use with the ability to protect themselves. This Program Project application is responsive to the stated objectives of announcement PA- 01-075; specifically, to advance development and optimization of lead topical microbicide candidates and to advance these microbicide candidates into pilot clinical studies. Biosyn, Inc. has assembled an outstanding team of scientists and drug development experts to specifically develop and advance cyanovirin-N (CV-N) as an anti-HIV topical microbicide. CV-N is one of the most interesting anti-HIV compounds available for microbicide development. Three separate research projects within the program will focus on: the production of CV-N protein in recombinant expression systems; the study of CVN formulation deployment in vitro and in vivo; and the feasibility of using CV-N in combination with other microbicide candidates as determined in an ex vivo system. These research projects will be supported by three cores which will be responsible for: administration and drug development; formulation, development; and virology testing. The iterative research and development efforts of these projects and cores will be a powerful means of rapidly and effectively advancing CV-N as an anti-HIV microbicide.